In crushing and grinding machines, for example roller mills with a separator arranged above, the material to be comminuted is delivered to the grinding chamber via a material feed chamber which is constructed as a chute or shaft and from which all of the material delivered passes into the region of the comminuting devices. However, prior to the grinding stage, this material often includes fines that need not go through the grinding process.
As a rule the material comminuted in the grinding chamber is then delivered pneumatically together with the fines already contained in the feed material to a separator arranged above the mill.
The object of the invention is to construct an apparatus for separating the fines of a material from a material stream in such a way as to achieve a substantial increase in output of the part of the plant, particularly a crushing and grinding machine, arranged after the material delivery apparatus.